20979379361 has 4 divisors (see below), whose sum is σ = 21546389652. Its totient is φ = 20412369072.

The previous prime is 20979379357. The next prime is 20979379403. The reversal of 20979379361 is 16397397902.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16397397902 = 2 ⋅8198698951.

It can be written as a sum of positive squares in 2 ways, for example, as 14748645136 + 6230734225 = 121444^2 + 78935^2 .

It is a cyclic number.

It is not a de Polignac number, because 20979379361 - 2² = 20979379357 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20979379297 and 20979379306.

It is not an unprimeable number, because it can be changed into a prime (20979372361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 283505090 + ... + 283505163.

It is an arithmetic number, because the mean of its divisors is an integer number (5386597413).

Almost surely, 2^20979379361 is an apocalyptic number.

It is an amenable number.

20979379361 is a deficient number, since it is larger than the sum of its proper divisors (567010291).

20979379361 is an equidigital number, since it uses as much as digits as its factorization.

20979379361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 567010290.

The product of its (nonzero) digits is 3857868, while the sum is 56.

The spelling of 20979379361 in words is "twenty billion, nine hundred seventy-nine million, three hundred seventy-nine thousand, three hundred sixty-one".